[thirdparty/git.git] / xdiff-interface.c

#include "cache.h"
#include "config.h"
#include "xdiff-interface.h"
#include "xdiff/xtypes.h"
#include "xdiff/xdiffi.h"
#include "xdiff/xemit.h"
#include "xdiff/xmacros.h"
#include "xdiff/xutils.h"

struct xdiff_emit_state {
	xdiff_emit_consume_fn consume;
	void *consume_callback_data;
	struct strbuf remainder;
};

static int parse_num(char **cp_p, int *num_p)
{
	char *cp = *cp_p;
	int num = 0;

	while ('0' <= *cp && *cp <= '9')
		num = num * 10 + *cp++ - '0';
	if (!(cp - *cp_p))
		return -1;
	*cp_p = cp;
	*num_p = num;
	return 0;
}

int parse_hunk_header(char *line, int len,
		      int *ob, int *on,
		      int *nb, int *nn)
{
	char *cp;
	cp = line + 4;
	if (parse_num(&cp, ob)) {
	bad_line:
		return error("malformed diff output: %s", line);
	}
	if (*cp == ',') {
		cp++;
		if (parse_num(&cp, on))
			goto bad_line;
	}
	else
		*on = 1;
	if (*cp++ != ' ' || *cp++ != '+')
		goto bad_line;
	if (parse_num(&cp, nb))
		goto bad_line;
	if (*cp == ',') {
		cp++;
		if (parse_num(&cp, nn))
			goto bad_line;
	}
	else
		*nn = 1;
	return -!!memcmp(cp, " @@", 3);
}

static void consume_one(void *priv_, char *s, unsigned long size)
{
	struct xdiff_emit_state *priv = priv_;
	char *ep;
	while (size) {
		unsigned long this_size;
		ep = memchr(s, '\n', size);
		this_size = (ep == NULL) ? size : (ep - s + 1);
		priv->consume(priv->consume_callback_data, s, this_size);
		size -= this_size;
		s += this_size;
	}
}

static int xdiff_outf(void *priv_, mmbuffer_t *mb, int nbuf)
{
	struct xdiff_emit_state *priv = priv_;
	int i;

	for (i = 0; i < nbuf; i++) {
		if (mb[i].ptr[mb[i].size-1] != '\n') {
			/* Incomplete line */
			strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
			continue;
		}

		/* we have a complete line */
		if (!priv->remainder.len) {
			consume_one(priv, mb[i].ptr, mb[i].size);
			continue;
		}
		strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
		consume_one(priv, priv->remainder.buf, priv->remainder.len);
		strbuf_reset(&priv->remainder);
	}
	if (priv->remainder.len) {
		consume_one(priv, priv->remainder.buf, priv->remainder.len);
		strbuf_reset(&priv->remainder);
	}
	return 0;
}

/*
 * Trim down common substring at the end of the buffers,
 * but end on a complete line.
 */
static void trim_common_tail(mmfile_t *a, mmfile_t *b)
{
	const int blk = 1024;
	long trimmed = 0, recovered = 0;
	char *ap = a->ptr + a->size;
	char *bp = b->ptr + b->size;
	long smaller = (a->size < b->size) ? a->size : b->size;

	while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
		trimmed += blk;
		ap -= blk;
		bp -= blk;
	}

	while (recovered < trimmed)
		if (ap[recovered++] == '\n')
			break;
	a->size -= trimmed - recovered;
	b->size -= trimmed - recovered;
}

int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *xecb)
{
	mmfile_t a = *mf1;
	mmfile_t b = *mf2;

	if (mf1->size > MAX_XDIFF_SIZE || mf2->size > MAX_XDIFF_SIZE)
		return -1;

	if (!xecfg->ctxlen && !(xecfg->flags & XDL_EMIT_FUNCCONTEXT))
		trim_common_tail(&a, &b);

	return xdl_diff(&a, &b, xpp, xecfg, xecb);
}

int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
		  xdiff_emit_consume_fn fn, void *consume_callback_data,
		  xpparam_t const *xpp, xdemitconf_t const *xecfg)
{
	int ret;
	struct xdiff_emit_state state;
	xdemitcb_t ecb;

	memset(&state, 0, sizeof(state));
	state.consume = fn;
	state.consume_callback_data = consume_callback_data;
	memset(&ecb, 0, sizeof(ecb));
	ecb.outf = xdiff_outf;
	ecb.priv = &state;
	strbuf_init(&state.remainder, 0);
	ret = xdi_diff(mf1, mf2, xpp, xecfg, &ecb);
	strbuf_release(&state.remainder);
	return ret;
}

int read_mmfile(mmfile_t *ptr, const char *filename)
{
	struct stat st;
	FILE *f;
	size_t sz;

	if (stat(filename, &st))
		return error_errno("Could not stat %s", filename);
	if ((f = fopen(filename, "rb")) == NULL)
		return error_errno("Could not open %s", filename);
	sz = xsize_t(st.st_size);
	ptr->ptr = xmalloc(sz ? sz : 1);
	if (sz && fread(ptr->ptr, sz, 1, f) != 1) {
		fclose(f);
		return error("Could not read %s", filename);
	}
	fclose(f);
	ptr->size = sz;
	return 0;
}

void read_mmblob(mmfile_t *ptr, const struct object_id *oid)
{
	unsigned long size;
	enum object_type type;

	if (!oidcmp(oid, &null_oid)) {
		ptr->ptr = xstrdup("");
		ptr->size = 0;
		return;
	}

	ptr->ptr = read_sha1_file(oid->hash, &type, &size);
	if (!ptr->ptr || type != OBJ_BLOB)
		die("unable to read blob object %s", oid_to_hex(oid));
	ptr->size = size;
}

#define FIRST_FEW_BYTES 8000
int buffer_is_binary(const char *ptr, unsigned long size)
{
	if (FIRST_FEW_BYTES < size)
		size = FIRST_FEW_BYTES;
	return !!memchr(ptr, 0, size);
}

struct ff_regs {
	int nr;
	struct ff_reg {
		regex_t re;
		int negate;
	} *array;
};

static long ff_regexp(const char *line, long len,
		char *buffer, long buffer_size, void *priv)
{
	struct ff_regs *regs = priv;
	regmatch_t pmatch[2];
	int i;
	int result;

	/* Exclude terminating newline (and cr) from matching */
	if (len > 0 && line[len-1] == '\n') {
		if (len > 1 && line[len-2] == '\r')
			len -= 2;
		else
			len--;
	}

	for (i = 0; i < regs->nr; i++) {
		struct ff_reg *reg = regs->array + i;
		if (!regexec_buf(&reg->re, line, len, 2, pmatch, 0)) {
			if (reg->negate)
				return -1;
			break;
		}
	}
	if (regs->nr <= i)
		return -1;
	i = pmatch[1].rm_so >= 0 ? 1 : 0;
	line += pmatch[i].rm_so;
	result = pmatch[i].rm_eo - pmatch[i].rm_so;
	if (result > buffer_size)
		result = buffer_size;
	while (result > 0 && (isspace(line[result - 1])))
		result--;
	memcpy(buffer, line, result);
	return result;
}

void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value, int cflags)
{
	int i;
	struct ff_regs *regs;

	xecfg->find_func = ff_regexp;
	regs = xecfg->find_func_priv = xmalloc(sizeof(struct ff_regs));
	for (i = 0, regs->nr = 1; value[i]; i++)
		if (value[i] == '\n')
			regs->nr++;
	ALLOC_ARRAY(regs->array, regs->nr);
	for (i = 0; i < regs->nr; i++) {
		struct ff_reg *reg = regs->array + i;
		const char *ep = strchr(value, '\n'), *expression;
		char *buffer = NULL;

		reg->negate = (*value == '!');
		if (reg->negate && i == regs->nr - 1)
			die("Last expression must not be negated: %s", value);
		if (*value == '!')
			value++;
		if (ep)
			expression = buffer = xstrndup(value, ep - value);
		else
			expression = value;
		if (regcomp(&reg->re, expression, cflags))
			die("Invalid regexp to look for hunk header: %s", expression);
		free(buffer);
		value = ep + 1;
	}
}

void xdiff_clear_find_func(xdemitconf_t *xecfg)
{
	if (xecfg->find_func) {
		int i;
		struct ff_regs *regs = xecfg->find_func_priv;

		for (i = 0; i < regs->nr; i++)
			regfree(&regs->array[i].re);
		free(regs->array);
		free(regs);
		xecfg->find_func = NULL;
		xecfg->find_func_priv = NULL;
	}
}

unsigned long xdiff_hash_string(const char *s, size_t len, long flags)
{
	return xdl_hash_record(&s, s + len, flags);
}

int xdiff_compare_lines(const char *l1, long s1,
			const char *l2, long s2, long flags)
{
	return xdl_recmatch(l1, s1, l2, s2, flags);
}

int git_xmerge_style = -1;

int git_xmerge_config(const char *var, const char *value, void *cb)
{
	if (!strcmp(var, "merge.conflictstyle")) {
		if (!value)
			die("'%s' is not a boolean", var);
		if (!strcmp(value, "diff3"))
			git_xmerge_style = XDL_MERGE_DIFF3;
		else if (!strcmp(value, "merge"))
			git_xmerge_style = 0;
		else
			die("unknown style '%s' given for '%s'",
			    value, var);
		return 0;
	}
	return git_default_config(var, value, cb);
}
Commit	Line	Data
d9ea73e0	1	#include "cache.h"
b2141fc1	2	#include "config.h"
d9ea73e0	3	#include "xdiff-interface.h"
86295bb6 RS	4	#include "xdiff/xtypes.h"
	5	#include "xdiff/xdiffi.h"
	6	#include "xdiff/xemit.h"
	7	#include "xdiff/xmacros.h"
5ec8274b	8	#include "xdiff/xutils.h"
8a3f524b JH	9
	10	struct xdiff_emit_state {
	11	xdiff_emit_consume_fn consume;
	12	void *consume_callback_data;
	13	struct strbuf remainder;
	14	};
d9ea73e0	15
a0fd3146	16	static int parse_num(char *cp_p, int num_p)
c1e335a4 JH	17	{
c1e335a4 JH	18	char cp = cp_p;
a0fd3146	19	int num = 0;
c1e335a4 JH	20
	21	while ('0' <= cp && cp <= '9')
	22	num = num * 10 + *cp++ - '0';
eb3a9dd3	23	if (!(cp - *cp_p))
c1e335a4 JH	24	return -1;
	25	*cp_p = cp;
	26	*num_p = num;
	27	return 0;
	28	}
	29
	30	int parse_hunk_header(char *line, int len,
a0fd3146 JH	31	int ob, int on,
a0fd3146 JH	32	int nb, int nn)
c1e335a4 JH	33	{
	34	char *cp;
	35	cp = line + 4;
	36	if (parse_num(&cp, ob)) {
	37	bad_line:
	38	return error("malformed diff output: %s", line);
	39	}
	40	if (*cp == ',') {
	41	cp++;
	42	if (parse_num(&cp, on))
	43	goto bad_line;
	44	}
	45	else
	46	*on = 1;
	47	if (cp++ != ' ' \|\| cp++ != '+')
	48	goto bad_line;
	49	if (parse_num(&cp, nb))
	50	goto bad_line;
	51	if (*cp == ',') {
	52	cp++;
	53	if (parse_num(&cp, nn))
	54	goto bad_line;
	55	}
	56	else
	57	*nn = 1;
	58	return -!!memcmp(cp, " @@", 3);
	59	}
	60
d9ea73e0 JH	61	static void consume_one(void priv_, char s, unsigned long size)
	62	{
	63	struct xdiff_emit_state *priv = priv_;
	64	char *ep;
	65	while (size) {
	66	unsigned long this_size;
	67	ep = memchr(s, '\n', size);
	68	this_size = (ep == NULL) ? size : (ep - s + 1);
8a3f524b	69	priv->consume(priv->consume_callback_data, s, this_size);
d9ea73e0 JH	70	size -= this_size;
	71	s += this_size;
	72	}
	73	}
	74
c99db9d2	75	static int xdiff_outf(void priv_, mmbuffer_t mb, int nbuf)
d9ea73e0 JH	76	{
	77	struct xdiff_emit_state *priv = priv_;
	78	int i;
	79
	80	for (i = 0; i < nbuf; i++) {
	81	if (mb[i].ptr[mb[i].size-1] != '\n') {
	82	/* Incomplete line */
b4637760	83	strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
d9ea73e0 JH	84	continue;
	85	}
	86
	87	/* we have a complete line */
b4637760	88	if (!priv->remainder.len) {
d9ea73e0 JH	89	consume_one(priv, mb[i].ptr, mb[i].size);
	90	continue;
	91	}
b4637760 BD	92	strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
	93	consume_one(priv, priv->remainder.buf, priv->remainder.len);
	94	strbuf_reset(&priv->remainder);
d9ea73e0	95	}
b4637760 BD	96	if (priv->remainder.len) {
	97	consume_one(priv, priv->remainder.buf, priv->remainder.len);
	98	strbuf_reset(&priv->remainder);
d9ea73e0 JH	99	}
	100	return 0;
	101	}
7cab5883	102
913b45f5 JH	103	/*
913b45f5 JH	104	* Trim down common substring at the end of the buffers,
e0876bca	105	* but end on a complete line.
913b45f5	106	*/
e0876bca	107	static void trim_common_tail(mmfile_t a, mmfile_t b)
913b45f5 JH	108	{
913b45f5 JH	109	const int blk = 1024;
52499977	110	long trimmed = 0, recovered = 0;
913b45f5 JH	111	char *ap = a->ptr + a->size;
	112	char *bp = b->ptr + b->size;
	113	long smaller = (a->size < b->size) ? a->size : b->size;
	114
	115	while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
	116	trimmed += blk;
	117	ap -= blk;
	118	bp -= blk;
	119	}
	120
d2f82950	121	while (recovered < trimmed)
52499977	122	if (ap[recovered++] == '\n')
d2f82950 LT	123	break;
	124	a->size -= trimmed - recovered;
	125	b->size -= trimmed - recovered;
913b45f5 JH	126	}
913b45f5 JH	127
c279d7e9 JH	128	int xdi_diff(mmfile_t mf1, mmfile_t mf2, xpparam_t const xpp, xdemitconf_t const xecfg, xdemitcb_t *xecb)
c279d7e9 JH	129	{
913b45f5 JH	130	mmfile_t a = *mf1;
	131	mmfile_t b = *mf2;
	132
dcd1742e JK	133	if (mf1->size > MAX_XDIFF_SIZE \|\| mf2->size > MAX_XDIFF_SIZE)
	134	return -1;
	135
e0876bca RS	136	if (!xecfg->ctxlen && !(xecfg->flags & XDL_EMIT_FUNCCONTEXT))
e0876bca RS	137	trim_common_tail(&a, &b);
913b45f5 JH	138
913b45f5 JH	139	return xdl_diff(&a, &b, xpp, xecfg, xecb);
c279d7e9 JH	140	}
c279d7e9 JH	141
c99db9d2	142	int xdi_diff_outf(mmfile_t mf1, mmfile_t mf2,
8a3f524b	143	xdiff_emit_consume_fn fn, void *consume_callback_data,
dfea7900	144	xpparam_t const xpp, xdemitconf_t const xecfg)
c99db9d2 BD	145	{
c99db9d2 BD	146	int ret;
8a3f524b	147	struct xdiff_emit_state state;
dfea7900	148	xdemitcb_t ecb;
8a3f524b JH	149
	150	memset(&state, 0, sizeof(state));
	151	state.consume = fn;
	152	state.consume_callback_data = consume_callback_data;
dfea7900 RS	153	memset(&ecb, 0, sizeof(ecb));
	154	ecb.outf = xdiff_outf;
	155	ecb.priv = &state;
8a3f524b	156	strbuf_init(&state.remainder, 0);
dfea7900	157	ret = xdi_diff(mf1, mf2, xpp, xecfg, &ecb);
8a3f524b	158	strbuf_release(&state.remainder);
c99db9d2 BD	159	return ret;
	160	}
	161
7cab5883 JS	162	int read_mmfile(mmfile_t ptr, const char filename)
	163	{
	164	struct stat st;
	165	FILE *f;
dc49cd76	166	size_t sz;
7cab5883 JS	167
7cab5883 JS	168	if (stat(filename, &st))
5118d7f4	169	return error_errno("Could not stat %s", filename);
7cab5883	170	if ((f = fopen(filename, "rb")) == NULL)
5118d7f4	171	return error_errno("Could not open %s", filename);
dc49cd76	172	sz = xsize_t(st.st_size);
381b851c	173	ptr->ptr = xmalloc(sz ? sz : 1);
5fd89814 RS	174	if (sz && fread(ptr->ptr, sz, 1, f) != 1) {
5fd89814 RS	175	fclose(f);
7cab5883	176	return error("Could not read %s", filename);
5fd89814	177	}
7cab5883	178	fclose(f);
dc49cd76	179	ptr->size = sz;
7cab5883 JS	180	return 0;
	181	}
	182
d449347d	183	void read_mmblob(mmfile_t ptr, const struct object_id oid)
06b65939 ML	184	{
	185	unsigned long size;
	186	enum object_type type;
	187
d449347d	188	if (!oidcmp(oid, &null_oid)) {
06b65939 ML	189	ptr->ptr = xstrdup("");
	190	ptr->size = 0;
	191	return;
	192	}
	193
d449347d	194	ptr->ptr = read_sha1_file(oid->hash, &type, &size);
06b65939	195	if (!ptr->ptr \|\| type != OBJ_BLOB)
d449347d	196	die("unable to read blob object %s", oid_to_hex(oid));
06b65939 ML	197	ptr->size = size;
	198	}
	199
6bfce93e JS	200	#define FIRST_FEW_BYTES 8000
	201	int buffer_is_binary(const char *ptr, unsigned long size)
	202	{
	203	if (FIRST_FEW_BYTES < size)
	204	size = FIRST_FEW_BYTES;
	205	return !!memchr(ptr, 0, size);
	206	}
f258475a JH	207
	208	struct ff_regs {
	209	int nr;
	210	struct ff_reg {
	211	regex_t re;
	212	int negate;
	213	} *array;
	214	};
	215
	216	static long ff_regexp(const char *line, long len,
	217	char buffer, long buffer_size, void priv)
	218	{
f258475a JH	219	struct ff_regs *regs = priv;
f258475a JH	220	regmatch_t pmatch[2];
3d8dccd7	221	int i;
b7d36ffc	222	int result;
f258475a	223
a5a5a048 BC	224	/* Exclude terminating newline (and cr) from matching */
a5a5a048 BC	225	if (len > 0 && line[len-1] == '\n') {
46dc1b0e JH	226	if (len > 1 && line[len-2] == '\r')
	227	len -= 2;
	228	else
	229	len--;
	230	}
	231
f258475a JH	232	for (i = 0; i < regs->nr; i++) {
f258475a JH	233	struct ff_reg *reg = regs->array + i;
b7d36ffc	234	if (!regexec_buf(&reg->re, line, len, 2, pmatch, 0)) {
3d8dccd7	235	if (reg->negate)
b7d36ffc	236	return -1;
3d8dccd7	237	break;
f258475a JH	238	}
f258475a JH	239	}
3d8dccd7	240	if (regs->nr <= i)
b7d36ffc	241	return -1;
f258475a JH	242	i = pmatch[1].rm_so >= 0 ? 1 : 0;
	243	line += pmatch[i].rm_so;
	244	result = pmatch[i].rm_eo - pmatch[i].rm_so;
	245	if (result > buffer_size)
	246	result = buffer_size;
1b6ecbad BC	247	while (result > 0 && (isspace(line[result - 1])))
1b6ecbad BC	248	result--;
f258475a	249	memcpy(buffer, line, result);
f258475a JH	250	return result;
	251	}
	252
a013585b	253	void xdiff_set_find_func(xdemitconf_t xecfg, const char value, int cflags)
f258475a JH	254	{
	255	int i;
	256	struct ff_regs *regs;
	257
	258	xecfg->find_func = ff_regexp;
	259	regs = xecfg->find_func_priv = xmalloc(sizeof(struct ff_regs));
	260	for (i = 0, regs->nr = 1; value[i]; i++)
	261	if (value[i] == '\n')
	262	regs->nr++;
b32fa95f	263	ALLOC_ARRAY(regs->array, regs->nr);
f258475a JH	264	for (i = 0; i < regs->nr; i++) {
	265	struct ff_reg *reg = regs->array + i;
	266	const char ep = strchr(value, '\n'), expression;
	267	char *buffer = NULL;
	268
	269	reg->negate = (*value == '!');
	270	if (reg->negate && i == regs->nr - 1)
	271	die("Last expression must not be negated: %s", value);
	272	if (*value == '!')
	273	value++;
	274	if (ep)
	275	expression = buffer = xstrndup(value, ep - value);
	276	else
	277	expression = value;
a013585b	278	if (regcomp(&reg->re, expression, cflags))
f258475a	279	die("Invalid regexp to look for hunk header: %s", expression);
8e0f7003	280	free(buffer);
f258475a JH	281	value = ep + 1;
	282	}
	283	}
b5412484	284
8cfe5f1c RS	285	void xdiff_clear_find_func(xdemitconf_t *xecfg)
	286	{
	287	if (xecfg->find_func) {
	288	int i;
	289	struct ff_regs *regs = xecfg->find_func_priv;
	290
	291	for (i = 0; i < regs->nr; i++)
	292	regfree(&regs->array[i].re);
	293	free(regs->array);
	294	free(regs);
	295	xecfg->find_func = NULL;
	296	xecfg->find_func_priv = NULL;
	297	}
	298	}
	299
5ec8274b SB	300	unsigned long xdiff_hash_string(const char *s, size_t len, long flags)
	301	{
	302	return xdl_hash_record(&s, s + len, flags);
	303	}
	304
	305	int xdiff_compare_lines(const char *l1, long s1,
	306	const char *l2, long s2, long flags)
	307	{
	308	return xdl_recmatch(l1, s1, l2, s2, flags);
	309	}
	310
b5412484 JH	311	int git_xmerge_style = -1;
	312
	313	int git_xmerge_config(const char var, const char value, void *cb)
	314	{
8c2be75f	315	if (!strcmp(var, "merge.conflictstyle")) {
b5412484 JH	316	if (!value)
	317	die("'%s' is not a boolean", var);
	318	if (!strcmp(value, "diff3"))
	319	git_xmerge_style = XDL_MERGE_DIFF3;
	320	else if (!strcmp(value, "merge"))
	321	git_xmerge_style = 0;
	322	else
	323	die("unknown style '%s' given for '%s'",
	324	value, var);
	325	return 0;
	326	}
	327	return git_default_config(var, value, cb);
	328	}